//201902104003邵潇漩
package bysj.controller.basic;
import bysj.domain.Degree;
import bysj.service.DegreeService;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.serializer.SerializerFeature;

import lombok.extern.slf4j.Slf4j;
import util.Condition;
import util.ControllerHelper;
import util.JSONUtil;
import util.Pagination;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Collection;
import java.util.List;

/**
 * @author shaoxiaoxuann@163.com
 * @version 1.0  10-31-2020
 * DegreeController
 */
@Slf4j
@WebServlet("/degree.ctl")
public class DegreeController extends HttpServlet {
    /**
     * POST, http://localhost:8080/degree.ctl, 增加学位
     * 增加一个学位对象：将来自前端请求的JSON对象，增加到数据库表中
     * @param request 请求对象
     * @param response 响应对象
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //设置请求字符编码为UTF-8
        //request.setCharacterEncoding("UTF-8");
        //根据request对象，获得代表参数的JSON字串
        String degree_json = JSONUtil.getJSON(request);
        //将JSON字串解析为Degree对象
        Degree degreeToAdd = JSON.parseObject(degree_json, Degree.class);
        //设置响应字符编码为UTF-8
        //response.setContentType("application/json;charset=UTF-8");
        //创建JSON对象message，以便往前端响应信息
        JSONObject message = new JSONObject();
        //在数据库表中增加Degree对象
        try {
            DegreeService.getInstance().add(degreeToAdd);
            message.put("message", "增加成功");
        }catch (SQLException e){
            message.put("message", "数据库操作异常");
            log.error("数据库操作异常:"+e);
        }catch(Exception e){
            message.put("message", "网络异常");
            log.error("网络异常:"+e);
        }
        //响应message到前端
        response.getWriter().println(message);
    }

    /**
     * DELETE, http://localhost:8080/degree.ctl?id=1, 删除id=1的学位
     * 删除一个学位对象：根据来自前端请求的id，删除数据库表中id的对应记录
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doDelete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //将request body转换为JSON字串
        String req_jsonStr = JSONUtil.getJSON(request);
        //将request body解析为JSONObject对象
        JSONObject req_jsonObj = JSON.parseObject(req_jsonStr);
        //从JSONObject对象中读取键“id”的值（Java Object对象），req_jsonObj可能是{"id":1}
        Object id_obj = req_jsonObj.get("id");
        int id_int = Integer.parseInt(id_obj.toString());
        log.info("id="+id_int);
        //设置响应字符编码为UTF-8
        //response.setContentType("application/json;charset=UTF-8");
        //创建JSON对象message，以便往前端响应信息
        JSONObject message = new JSONObject();
        //到数据库表中删除对应的学位
        try {
            DegreeService.getInstance().delete(id_int);
            message.put("message", "删除成功");
        }catch (SQLException e){
            message.put("message", "数据库操作异常");
            log.error("数据库操作异常:"+e);
        }catch(Exception e){
            message.put("message", "网络异常");
            log.error("网络异常:"+e);
        }
        //响应message到前端
        response.getWriter().println(message);
    }


    /**
     * PUT, http://localhost:8080/degree.ctl, 修改学位
     *
     * 修改一个学位对象：将来自前端请求的JSON对象，更新数据库表中相同id的记录
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doPut(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //设置请求字符编码为UTF-8
        //request.setCharacterEncoding("UTF-8");
        String degree_json = JSONUtil.getJSON(request);
        //将JSON字串解析为Degree对象
        Degree degree = JSON.parseObject(degree_json, Degree.class);
        //设置响应字符编码为UTF-8
        //response.setContentType("application/json;charset=UTF-8");
        //创建JSON对象message，以便往前端响应信息
        JSONObject message = new JSONObject();
        //到数据库表修改Degree对象对应的记录
        try {
            DegreeService.getInstance().update(degree);
            message.put("message", "修改成功");
        }catch (SQLException e){
            message.put("message", "数据库操作异常");
            log.error("数据库操作异常:"+e);
        }catch(Exception e){
            message.put("message", "网络异常");
            log.error("网络异常:"+e);
        }
        //响应message到前端
        response.getWriter().println(message);
    }

    /**
     * GET, http://localhost:8080/degree.ctl?id=1, 查询id=1的学位
     * GET, http://localhost:8080/degree.ctl, 查询所有的学位
     * 把一个或所有学位对象响应到前端
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //创建JSON对象respMessage_jsonObj，以便往前端响应信息
        JSONObject respMessage_jsonObj = new JSONObject();
        //设置响应字符编码为UTF-8
        //response.setContentType("application/json;charset=UTF-8");
        //将request body转换为JSON字串
        String req_jsonStr = JSONUtil.getJSON(request);
        //将request body解析为JSONObject对象
        JSONObject req_jsonObj = JSON.parseObject(req_jsonStr);
        //如果请求body为空
        if (req_jsonObj == null) {
            respMessage_jsonObj.put("message","未收到请求信息！");
            response.getWriter().println(respMessage_jsonObj);
            return;
        }
        //从JSONObject对象中读取键“id”的值（Java Object对象），req_jsonObj可能是{"id":1}
        Object id_obj = req_jsonObj.get("id");
        try {
            //如果id_Obj != null, 说明请求数据有id键，是请求某个教师对象
            if (id_obj != null) {
                int id_int = Integer.parseInt(id_obj.toString());
                responseDegree(id_int, response);
                log.info("id="+id_int);
            } else {//请求中包含条件和分页信息，需要响应多个教师对象
                //读取分页信息，形成分页对象
                //从JSONObject对象中读取 “pagination” 键对应的值(JSONObject对象)
                Pagination pagination = ControllerHelper.getPagination(req_jsonObj);
                //从请求JSONObject对象中读取键“conditionList”对应的值(描述查询条件的JSONArray对象)
                List<Condition> conditionList = ControllerHelper.getConditions(req_jsonObj);
                //响应多个学位信息，其中conditionList, pagination两个对象引用为空是可能的
                this.responseDegrees(response, pagination,conditionList);
            }
        } catch (SQLException e) {
            respMessage_jsonObj.put("message", "数据库操作异常");
            //响应respMessage_jsonObj到前端
            response.getWriter().println(respMessage_jsonObj);
            //打印异常栈，方便调试（要用log4j代替）
            log.error("数据库操作异常:"+e);
        } catch (Exception e) {
            respMessage_jsonObj.put("message", "网络异常");
            //响应respMessage_jsonObj到前端
            response.getWriter().println(respMessage_jsonObj);
            //打印异常栈，方便调试（要用log4j代替）
            log.error("网络异常:"+e);
        }
    }
    //响应一个学位对象
    private void responseDegree(int id, HttpServletResponse response)
            throws ServletException, IOException, SQLException {
        //根据id查找学位
        Degree degree = DegreeService.getInstance().find(id);
        String degree_json = JSON.toJSONString(degree);

        //响应degree_json到前端
        response.getWriter().println(degree_json);
    }
    //响应所有学位对象
    private void responseDegrees(HttpServletResponse response,Pagination pagination,List<Condition> conditionList)
            throws ServletException, IOException, SQLException {
        //获得满足条件的所有院系
        Collection<Degree> degrees = DegreeService.getInstance().findAll(conditionList,pagination);
        String degree_json = JSON.toJSONString(degrees,SerializerFeature.DisableCircularReferenceDetect);
        JSONObject response_json = new JSONObject();
        response_json.put("totalNum" ,pagination.getTotalNum());
        response_json.put("data",degree_json);
        //响应department_json 到前端
        response.getWriter().println(response_json);
    }
    //得到一个Logger对象，**.class是将要加入日志的类加进入
    //private final Logger logger = Logger.getLogger(DegreeController.class);
}
